Second, compact, advanced, and highly reliable fusion generators are
available in a broad variety of sizes. Star Trek's microfusion cells
have been seen in smaller sizes than the smallest generator from TESB,
but this does not necessarily indicate either side has more advanced
fusion technology. Fusion technology is used extensively by both sides,
and are found on nearly every sort of device and vehicle.

Critically, however, fusion generators are placed in the back seat for
Star Trek starships. Although fusion generators are typically present
as
secondary systems, the primary generator of a Trek warship is an
antimatter plant or artificial quantum singularity. Even in terms of
space, a 100% efficient fusion generator burning metallic deuterium
pellets requires seven times the cubage of fuel for the same effect as
a slush antideuterium reactor, and a hundred times the mass of fuel. A
singularity with a radius of R has a maximum energy of 6.07x1043R
joules.

Of particular interest is the matchup between the power plants of
Imperial and Federation ships. Although little can be said directly
about the power
outputs of the two, their energy reserves can be very well analyzed.
Federation vessels use deuterium-fueled impulse engines (100-115 TJ/L,
630-740 TJ/kg)
and deuterium/antideuterium fueled warp engines (14,800 TJ/L, 90,000
TJ/kg), while
Imperial vessels use diesel-fueled fusion engines (70-230 TJ/L, 100-280
TJ/kg). For various reasons,
the high end of this range is likely for Imperial vessels, while the
low end is likely
for impulse vessels.

It is not too unlikely, therefore, that an Imperial vessel will get
over twice times as much energy per liter of fuel as an equivalent
impulse-fueled Federation vessel; however, a warp powered vessel with
the equivalent volume available for fuel and equipment will have 64-210
times the energy reserve. In both cases,
the Federation vessel enjoys an advantage in fuel mass. There remains a
certain tactical disadvantage
for the Federation vessels in that antimatter will spontaneously
explode far more violently than diesel fuel, given an opportunity;
however, the strategic advantage of being
able to field smaller ships of greater power and/or endurance is
substantial.